Paper-making machine



J. D. TOMFKINS PAPER mmm MACHXNE Filled oct. 5,

Jam L. N24

' particularly prior tothe passage of thaweby Patented dan. l, 1924.

ij T ST rss- J'OHN D. TUHPKINS, OF V'AJIA'ILIIE, NEW YORK.

asians rara ries.

PAPERPMAKING MACHINE Application lled October 5, 1921. Serial No. 505,574.l

The invention has for an object to'enableA a larger percentage of moisture to be removed from a 'newly formed paper`web as the s e passes through the machine,

between the press rolls which are employed in machines of the accepted type,.thus leaving less moisture tobe` removed by the action of the press rolls, "permitting the ma! chine to be operated safely at a higher speed, and avoiding the necessity of subjecting the paper web and felt aprons to excessive pressure when passing between the press rolls.

Another object of the invention is to facilitate the disengagement of the paper web from the lower press felt apron, particularly when the lower felt .apron is ofthe suction type.A

Further objects and advantages of the` invention will be in part lobvious and in part 4specifically pointed out in the description hereinafter contained which, 'taken in connection with the accompanying drawings, discloses a preferred embodiment of the invention; such embodiment, however,l is to be consideretd as merely illustrative of its principle. In the drawings:

The single figure is a diagrammatic vertical longitudinal section showing a paper making machine adapted to operateI in accordance with the invention. v'

In accordance with the present invention', the moisture is removed from thel porous fibrous structure of a newly formed paper web before the fibers have been closely pressed together, by passing air under pressure through the web sc asto evaporate and carry ed a large percentageof moisture.A

l prefer to subject the paper web to an air blast of the above character while the web is carried between the upper and lower felt aprons, toniinimize the danger of liber displacement or liber bond injury, vand also to employ a lower press roll 'of the suction type' and so relate the same to the air blast thatl the combined action of the air pressure and suction will serve to draw moisture very rapidly from the paper web before the latter is subjected to the pinch of the press rolls,

thereby avoiding galling ofthe pper web by the press-water when the macnn'eis runu ning at high speed.

Referring-to the drawing, the particular type of paper making machine illustrated embodies a paper web forming means eomprisinv a forming wirel l running overa plurality of small rolls 2, and around a lower couch roll 3. `The newly formed paper web 4 is-transferred from forming wire 1 to the upper felt apron 5, which is pressed into engagement therewith by` means of an upper couch roll 6, the upper felt apron passing between the upper and lower'press rolls 7 and 8 respectively, and in the present instance also serving to carry the paper vweb from the press rolls to the first roll 9 of a series of dryers by passing around a roller 10 -which presses against roll. 9. A. lower felt apron l1 passes overa roller l2 located in advance of the press rolls or between the same and the web forming means, such lower felt apron also passing, between press rolls 7 and 8, and thus as the paper web 'is fed to the'press rolls it is held between the felt'` aprons and 11. As the specific structure ofthe machine as a whole is not essential 'can be passed through ythe machine, since if too much water is pressedout at the -press rolls the accumulation of water 4at the press. rolls tends to create a back pressure which produces -eurdlingor galling ofthe web.

Furthermore, if it becomes necessary to re move a too large amount of water at the press rolls, the excessive roll pressuretends toweaken the fiber bond of the paper web,

and to injure the'- felt aprons. Or, if a plurality 4ofsets of press rolls be employed to squeeze out the water from the web in successive stages in order to eliminate the.

above difficulty, the expense and size of the machine of course are increased.

p In order to reduce the amount of water to be removed by the pressi-.olla subject the newly formed paper web to a blast of compressed air, preferably as dry as possible. and warm, at a temperature in the neighborhood of 100 F., the air blast. being to the present invention, the same will not supplied by suitable means such as the pipe 13, having perforations 14 therein directed toward the paper web. The pipe 13 is disposed in advance of the press rolls, and the air passing therefrom through the fibers of the web serves to carry olf a substantial percentage of the moisture therefrom, thus reducing the amount of water necessary to be squeezed out by the press rolls, and permitting the machine to be operated at higher speed, and without excessive pressures between rolls 7 and 8. Ordinarily, the machine may be operated at high speed with only one set of press rolls, under the above conditions.

The air blast preferably is directed through the paper web while the latter is carried between the upper and lower felt aprons 5 and l1, in order to prevent fiber displacement or liber bond injury. Also the action of the compressed air upon the paper web preferably is augmented by employing a lower press roll 8 of thesuction type, and locating the pipe 13 adjacent the active suction area of the roll. The air blast then passes readily through the porous structure v of the feltaprons and the paper web, with the result that the paper web goes to the dryers with less displacement of fiber, or bond injury and with less moisture than otherwise would be the case, and the resulting paper product more nearly equals an air or loft-dried product, especially if the machine be run at relatively low speed.

The lower press roll 8 will be understood as of well-known construction (not illustrated) whereby the 'suction area thereof is limited substantiall to the arc of engagement of the paper we therewith. I prefer to locate the lower press roll 8 somewhat in advance of the upper press roll 7 in such manner that the upper press roll bears upon the lower press roll substantially at the forward limit of the suction area of the latter. Thus there is less danger of thepaper web being pulled away from the upper felt apron 5 by the suctionof the lower press roll, after the web leaves the press rolls, and furthermore if `the pipe 13 be located above the lower press roll as illustrated, a large arc of exposure ofthe paper web and felt aprons to the combined actionof the air blast and the suction of the lower press roll will be obtained.

While a specific embodiment of the invention has been describethit will be obvious that many changes may be made therein without departing from the principle of the invention. as defined in the following claims.

l claim;

l. A paper making machine comprising means for forming a paper web, upper and lower press rolls, upper and lower felt aprons passing between said press rolls and :ulapted to carry the paper web thereto, and

lawaai..

means located in advance of said press rolls for forcing air under greater than atmospress roll, and a lower press roll of the suction type, upper and lower felt aprons passing La: een said press rolls and adapted to lead the paper web thereto, and means located in advance of the press rolls and adjacent the suction area of the lower press roll for forcing air under greater than atmosphericpressure through said felt aprons and the paper web carried therebetween.

4. The method of making paper which comprises forming a paper web, conducting said web between press rolls while supported by a feltvaprony and forcing air under greater than atmospheric pressure through said web in advance of the ress rolls while the web is supported by sai felt apron.

5. A paper making machine comprising mea-ns for forming a paper web, an upper press roll, and a lower press roll of the suc tion type, upper and lower felt ,aprons passing between said press rolls, the lower press roll being located in advance of the upper press roll whereby the lupper press roll presses the felt aprons toward a point on the lower press roll which is substantially at the rearward limit of the suction area thereof, and means disposed adjacent the suction area of the lower press roll for forcing air Linder greater than latmospheric pressure throu h the felt aprons and the paper web carr' thereby.

6. The method of making paper which comprises forming a'paper web, conducting said web between upper and lower carrying mediums to press rolls and forcing air under greater than atmospheric pressure through said web in advance of the press rolls while supported between said carrying mediums.

7'. The method of making paper which comprises forming a paper` web, conducting the same between upper and lower felt aprons, passing said aprons between upper and lower press rolls, and forcing air under greater than atmospheric pressure through the paper web while the latter is carried between the felt aprons and in advance of the press rolls. l

9. The method of making paper which comprises forming a paper web, conducting said web between upper and lower carrying mediums to press rolls, forcing air under 1o and lower press rolls,

greater than atmospheric pressure through said web in advance of the press rolls While supported between said carrying mediums and simultaneously subjecting the opposite side of the web to suction.

9. The method of making paper which vcomprises forming a paper web, conducting the same between upper and lower. felt aprons, passing sald aprons between upper forcing air under greater than atmospheric pressure through the paper web While the latter is, carried between the felt aprons and in advance of the press rolls and simultaneously subjecting the opposite side of the web to suction,

In testimony that I claim the foregoing, I have hereunto set my hand this 28day of September, 1921.

JOHN D. Toi/trarne. 

